A compressive sensing-based coping mechanism against sensing unit failure of hemisphere-shaped electrostatic sensors' circular array

When faults happen at gas path components of gas turbines, some charged abnormal debris will be generated. An electrostatic sensor can be installed at the tail end of the exhaust pipe to monitor the abnormal debris online and further indicate the faults. However, the electrostatic sensor itself is faced with a problem of function failure because of a severe working condition of high temperature and strong vibration. As for a commonly-used electrostatic monitoring system that contains only one electrostatic sensor, the failure of the only sensor will result in a complete failure of the whole system. Therefore, in order to improve the robustness of electrostatic monitoring, hemisphere-shaped electrostatic sensors are used as sensing units to constitute a circular array, and a compressive sensing-based array signal processing algorithm along with a coping mechanism against sensing unit failure is proposed in this paper. Simulation results show that the array signal processing algorithm can effectively monitor position and charge of the abnormal debris, and the coping mechanism enables the system to maintain a sufficient monitoring precision when sensing unit failure occurs.